Among the top puzzles in the development of fusion energy is the best shape for the magnetic facility — or “bottle” — that will provide the next steps in the development of fusion reactors. Leading candidates include spherical tokamaks, compact machines that are shaped like cored apples, compared with the doughnut-like shape of conventional tokamaks. The spherical design produces high-pressure plasmas — essential ingredients for fusion reactions — with relatively low and cost-effective magnetic fields.

Runaway electrons, a searing, laser-like beam of electric current released by plasma disruptions, could damage the interior walls of future tokamaks the size of ITER, the international fusion experiment under construction in France. To help overcome this challenge, leading experts in the field have launched a multi-institutional center to find ways to prevent or mitigate such events.

Runaway electrons, a searing, laser-like beam of electric current released by plasma disruptions, could damage the interior walls of future tokamaks the size of ITER, the international fusion experiment under construction in France. To help overcome this challenge, leading experts in the field have launched a multi-institutional center to find ways to prevent or mitigate such events.

"Chirp, chirp, chirp." The familiar sound of birds is also what researchers call a wave in plasma that breaks from a single note into rapidly changing notes. This behavior can cause heat in the form of high energy particles — or fast ions — to leak from the core of plasma inside tokamaks — doughnut-shaped facilities that house fusion reactions.

"Chirp, chirp, chirp." The familiar sound of birds is also what researchers call a wave in plasma that breaks from a single note into rapidly changing notes. This behavior can cause heat in the form of high energy particles — or fast ions — to leak from the core of plasma inside tokamaks — doughnut-shaped facilities that house fusion reactions.

Chaos was discovered near the end of the 19th century in the seminal work of Henri Poincare. However, widespread impact of chaotic dynamics accompanied by rapid development of understand did not occur until a relatively long after Poincare's work (of the order of 90 years). This talk will review some this history and give some examples illustrating the broad range of these more recent developments and applications.

Physicists led by Gerrit Kramer at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) have conducted simulations that suggest that applying magnetic fields to fusion plasmas can control instabilities known as Alfvén waves that can reduce the efficiency of fusion reactions. Such instabilities can cause quickly moving charged particles called "fast ions" to escape from the core of the plasma, which is corralled within machines known as tokamaks.